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Isotopes of the Element Polonium

[Click for Main Data]

Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information.

Naturally Occurring Isotopes

Polonium has no naturally occurring isotopes.

Known Isotopes

Mass NumberHalf-lifeDecay ModeBranching Percentage
186No Data AvailableNo Data AvailableNo Data Available
1871.40 millisecondsAlpha Decay100.00%
1880.275 millisecondsElectron Capture100.00%
Alpha DecayNo Data Available
1893.5 millisecondsAlpha Decay100.00%
1902.46 millisecondsAlpha Decay100.00%
19122 millisecondsAlpha Decay99.00%
191m93 millisecondsAlpha Decay96.00%
19232.2 millisecondsAlpha Decay~ 99.50%
Electron Capture~ 0.50%
193245 millisecondsAlpha Decay<= 100.00%
193m370 millisecondsAlpha Decay<= 100.00%
1940.392 secondsAlpha Decay100.00%
Electron CaptureNo Data Available
1954.64 secondsAlpha Decay75.00%
Electron Capture25.00%
195m1.92 secondsElectron Capture~ 10.00%
Isomeric Transition< 0.01%
Alpha Decay~ 90.00%
1965.8 secondsAlpha Decay~ 98.00%
Electron Capture~ 2.00%
19784 secondsElectron Capture56.00%
Alpha Decay44.00%
197m32 secondsAlpha Decay84.00%
Electron Capture16.00%
Isomeric Transition0.01%
1981.77 minutesAlpha Decay57.00%
Electron Capture43.00%
1995.47 minutesElectron Capture92.50%
Alpha Decay7.50%
199m4.17 minutesElectron Capture73.50%
Alpha Decay24.00%
Isomeric Transition2.50%
20011.51 minutesElectron Capture88.90%
Alpha Decay11.10%
20115.6 minutesElectron Capture98.87%
Alpha Decay1.13%
201m8.96 minutesElectron Capture41.40%
Alpha Decay2.40%
Isomeric Transition56.20%
20244.6 minutesElectron Capture98.08%
Alpha Decay1.92%
20336.7 minutesElectron Capture99.89%
Alpha Decay0.11%
203m45 secondsIsomeric Transition100.00%
Electron CaptureNo Data Available
2043.519 hoursElectron Capture99.33%
Alpha Decay0.67%
2051.74 hoursAlpha Decay0.04%
Electron Capture99.96%
205m0.645 millisecondsIsomeric Transition100.00%
205m157.4 millisecondsIsomeric Transition100.00%
2068.8 daysElectron Capture94.55%
Alpha Decay5.45%
2075.80 hoursElectron Capture99.98%
Alpha Decay0.02%
207m2.79 secondsIsomeric Transition100.00%
2082.898 yearsAlpha Decay100.00%
Electron Capture4.0×10-3 %
209102 yearsElectron Capture0.48%
Alpha Decay99.52%
210138.376 daysAlpha Decay100.00%
2110.516 secondsAlpha Decay100.00%
211m25.2 secondsAlpha Decay99.98%
Isomeric Transition0.02%
2120.299 microsecondsAlpha Decay100.00%
212m45.1 secondsAlpha Decay99.93%
Isomeric Transition0.07%
2133.72 microsecondsAlpha Decay100.00%
214164.3 microsecondsAlpha Decay100.00%
2151.781 millisecondsAlpha Decay100.00%
Beta-minus Decay2.3×10-4 %
2160.145 secondsAlpha Decay100.00%
2171.53 secondsAlpha DecayNo Data Available
2183.098 minutesAlpha Decay99.98%
Beta-minus Decay0.02%
219> 300 nanosecondsBeta-minus DecayNo Data Available
220> 300 nanosecondsBeta-minus DecayNo Data Available
221112 secondsBeta-minus Decay (suspected)No Data Available
222550 secondsBeta-minus Decay (suspected)No Data Available
223> 300 nanosecondsBeta-minus DecayNo Data Available
224> 300 nanosecondsBeta-minus DecayNo Data Available
225> 300 nanosecondsBeta-minus DecayNo Data Available
226> 300 nanosecondsBeta-minus DecayNo Data Available
227> 300 nanosecondsBeta-minus DecayNo Data Available